Locomotives traditionally include a car body that houses one or more power units of the locomotive. The weight of the car body is supported at either end by trucks that transfer the weight to opposing rails. The trucks typically include cast steel frames that provide a mounting for traction motors, axles, and wheel sets. Locomotives can be equipped with trucks having two, three, or four axles. Although suitable for many applications, cast truck frames can be expensive, especially when produced in low numbers for specialized applications.
An exemplary fabricated locomotive truck is disclosed in JP Patent No. 2000085579A of Hitachi Ltd. that published on Mar. 28, 2000 (“the '579 patent”). Specifically, the '579 patent discloses a frame fabricated by welding a cast upper plate to a cast lower plate, such that integral U-shaped grooves are created at cross-sections of the frame. Cylindrical protrusions are formed at the lower plate and press-fitted into holes in the upper plate. Ends of the cylindrical protrusions are welded to edges of the holes, and seats are inserted into the cylindrical holes of the top plate. Springs, which ride on an axle bearing housing, extend into the cylindrical protrusions to suspend the frame above the associated axles.
Although perhaps suitable for some applications, the frame of the '579 patent may be less than optimal. In particular, because the springs push against the seats at the top plate, the length of the springs usable with the frame may be limited in length by the location of the top plate. In addition, the '579 patent does not disclose a way to limit separation of the bearing housing from the frame or to limit transverse movement of the frame. Further, separating the frame into two cast components may not significantly lower a production cost of the frame.
The frame of the present disclosure solves one or more of the problems set forth above and/or other problems in the art.